<?php
db_update('node')->fields(array(
		'comment' => 2
))
->condition('nid', 1)
->execute();

db_insert('comments')->fields(array(
		'cid',
		'pid',
		'nid',
		'uid',
		'subject',
		'comment',
		'hostname',
		'timestamp',
		'status',
		'format',
		'thread',
		'name',
		'mail',
		'homepage',
))
->values(array(
		'cid' => 1,
		'pid' => 0,
		'nid' => 1,
		'uid' => 3,
		'subject' => 'Comment title 1',
		'comment' => 'Comment body 1 - Comment body 1 - Comment body 1 - Comment body 1 - Comment body 1 - Comment body 1 - Comment body 1 - Comment body 1',
		'hostname' => '127.0.0.1',
		'timestamp' => 1008617630,
		'status' => 0,
		'format' => 1,
		'thread' => '01/',
		'name' => NULL,
		'mail' => NULL,
		'homepage' => '',
))
->execute();
